1. Field of the Invention
This invention relates to a connector produced by insert molding and a method for producing the connector.
2. Description of the Related Art
A connector produced by integrating a plurality of terminals with a housing by insert molding is disclosed, for example, in Japanese Patent Public Disclosure No. SHO 63-211577 (1988). The insert molding method places the terminals in a mold and then injects resin into the mold and around the terminals. However, it is inefficient to set a plurality of terminals one by one in a mold.
Accordingly, the terminals are connected through carriers to form a linked terminal. This process is effected by setting a linked terminal in a mold for primary molding, integrating the linked terminal with a primary molding portion by insert molding, and producing a primary molding article with the carriers exposed. Then, the carriers are cut off to separate the terminals from each other. The primary molding article is set in a mold for secondary molding to effect secondary molding. A secondary molding portion covers the carriers and terminals to form a secondary molding article. Thus, a connector is obtained from the secondary molding article.
To avoid a short circuit between the terminals in the above process, the carriers in the primary molding article are cut off. Heretofore, the carriers have been cut off over wide areas to define a great clearance between remaining portions of the adjacent terminals. However, the greater this cutting area is, the larger the cut chip becomes. If the cut chips are blended into a mold for secondary molding, the cut chips will cause short circuits between the terminals.
A connector having ends of terminals projecting from an outer surface of a resin molding portion has been known and is identified by the numeral 300 in FIG. 27 herein. The prior art connector 300 includes a primary molding article 301 integrating terminals 303 with a primary molding resin portion 302 by means of primary insert molding. A resin molding portion 305 is formed by integrating the primary molding article 301 with a secondary molding resin portion 104 by means of secondary insert molding. Ends 303A of the terminals 303 extend outward from the outer surface of the resin molding portion 305.
If the connector is produced through the two processes, a mold 306 for secondary molding is provided with a clipping portion 307 that contacts the outer surface of the primary molding article 301. The clipping portion 307 defines a cavity 308 for secondary molding enclosed by the outer surface of the primary molding article 301 and the inner surface of the mold 306 for secondary molding. A molten resin is injected into the cavity 308 for secondary molding to form a secondary molding resin portion 304.
The secondary molding resin portion 304 of the conventional connector 300 surrounds the projecting areas of the terminals 303 on the outer surface of the resin molding portion 305. Thus, it is necessary to bring the clipping portion 307 of the mold 306 for secondary molding into contact with the terminals 303 in the part of the clipping portion 307 corresponding to the projecting areas of the terminals 303. Consequently, it is necessary to provide narrow holes 309 in the clipping portion 307 for receiving the ends 303A of the terminals 303. This results in a complicated structure in the mold 306 for secondary molding.
In view of the above problems, a first object of the present invention is to surely prevent a short circuit between terminal members upon cutting off carriers between the terminal members. A second object of the present invention is to simplify a structure of a mold for secondary molding.
The present invention is directed to a connector and to a method for producing a connector wherein a linked terminal is formed by coupling a plurality of terminals to each other by carriers. A primary molding article is formed by integrating the linked terminal with a primary molding portion by a primary insert molding. The terminal members then are separated from each other by cutting off the carriers. The connector is formed by integrating the primary molding article having the cut-off carriers with a secondary molding portion by means of secondary insert molding. The connector is characterized in that the carriers are cut along single cutting lines of severance, and remaining portions of the cut carriers are bent to separate adjacent terminals from each other.
Since each carrier is cut along a single cutting line of severance, a cut chip is not produced. Accordingly, it is possible to prevent the terminals from causing a short circuit due to inclusion of the cut chips into the secondary molding portion. Also, the remaining portions caused by cutting the carriers are deformed and bent to separate the adjacent terminals from each other. Consequently, any short circuit between the terminals due to direct contact of the remaining portions can be avoided.
The invention also is directed to a connector produced by projecting ends of terminals from an outer surface of a resin molding portion. The terminals are integrated with a primary molding resin portion by means of primary insert molding to form a primary molding article. A cavity for secondary molding is enclosed by an outer surface of the primary molding article and an inner surface of a mold for secondary molding. A clipping portion is provided on the mold for secondary molding being brought into contact with the outer surface of the primary molding article. A molten resin is injected into the cavity for secondary molding to form a secondary molding resin portion that integrates the secondary molding resin portion with the primary molding article. The connector is characterized in that the ends of the terminals project from the exposed regions of the primary molding resin portion that are not covered by the secondary molding resin portion.
A linked terminal that has a plurality of terminals connected by carriers may be integrated with the primary molding resin portion by means of primary insert molding. Escape holes may be provided in the primary molding resin portion at areas corresponding to the carriers. The carriers are cut off above the escape holes to separate the terminals away from each other, and secondary insert molding is effected. The secondary molding resin portion entering the escape hole insulates the terminals separated by cutting off the carriers.
The primary molding resin portion may be coupled to the secondary molding resin portion on the outer surface in which an end of each escape hole is open. The escape holes and secondary molding resin portion are provided with latches that restrain separation of the primary and secondary molding resin portions by engagement of the latches.
The primary molding article may be formed by piling a plurality of primary molding assemblies in axial directions of the escape holes. Each primary molding assembly may be formed by integrating the terminals with a primary molding resin element by means of primary insert molding.
The invention also is directed to a method for producing a connector having ends of terminals projecting from an outer surface of a resin molding portion. The method comprises integrating the terminals with a primary molding resin portion by means of primary insert molding to form a primary molding article. The method continues by defining a cavity for secondary molding enclosed by an outer surface of the primary molding article and an inner surface of a mold for secondary molding with a clipping portion provided on the mold for secondary molding being brought into contact with the outer surface of the primary molding article. The method proceeds by injecting a molten resin into the cavity for secondary molding to form a secondary molding resin portion; and integrating the secondary molding resin portion with the primary molding article. Ends of the terminals project from exposed regions of the primary molding resin portion.
The ends of the terminals project from the primary molding resin portion. Thus, the secondary molding resin portion and cavity for secondary molding are disposed in an area different from the projecting areas of the terminals and the clipping portion of the mold for secondary molding also is at a position where the terminals do not contact the mold. Accordingly, it is not necessary to provide narrow holes for receiving the ends of the terminals in the clipping portion, thereby simplifying the structure of the mold for secondary molding.
The terminals can be set in the mold for primary insert molding in the form of the linked terminal in which the carriers connect the terminals. Thus, workability is improved in comparison with a conventional setting work of the individual terminals. Also, the carriers are cut off in the escape holes. Therefore, it is not necessary to remove a part of the primary molding resin portion in association with cutting off the carriers, thereby eliminating waste of materials. Since the secondary molding resin portion is between the terminals separated by cutting the carriers to insulate the terminals, it is possible to insulate the respective terminals from each other.
The latches are provided on the escape holes and secondary molding resin portion to engage the portions, even if the ends of the escape holes are joined to the secondary molding resin portion at the surface on which the ends are open. Thus, it is possible to restrain the primary and secondary molding portions from separating from each other.
If the terminal members are piled in the axial directions of the escape holes when the primary molding portions of the primary molding article are formed as a single piece, it will be impossible to open the mold, since the terminals interfere with forming of the escape holes.
With respect to the above matter, in the present invention, the primary molding assemblies in which the terminal members and primary molding resin elements are integrated by primary insert molding are piled in the axial directions of the escape holes to form the primary molding article. Consequently, it is not necessary to align the terminals to pile them in the axial directions of the escape holes. The terminals do not interfere with the opening action of the mold upon forming the escape holes.